One of the biggest climate problems has to do with what most people eat

A butcher arranges pieces of meat at his shop in Marseille, France Thomson Reuters Chances are that you believe in climate change, but would be furious if someone tried to take away your steak.

That's why activists at this year's U.N. climate summit in Paris are taking a gentle approach to tackling the world's greenhouse gas-intensive love affair with meat, ranging from offering lookalike plant burgers to suggesting a gradual weaning off animal protein.

"This is one of the most delicate issues with climate protection, because we all have our habits and diet is something quite holy for some people, not to be meddled with," said Jo Leinen, an omnivorous German member of the European Parliament.

Negotiators from nearly 200 countries are focusing mainly on reducing carbon dioxide output from industry in order to limit global warming, rather than on diet.

But the livestock sector is responsible for about 14.5 percent of global greenhouse gas emissions, through cows producing methane and production processes - comparable to all the direct emissions from cars, planes, ships and other transport.

On the sidelines of the summit, one American firm this week proposed one answer in the form of its "Impossible Burger". Made entirely from plants, the patty is intended to look and taste identical to beef, and produces a similar smell when grilled.

Impossible Foods founder Pat Brown said the burger, which costs about $5 a pound ($11/kg) to produce but should become cheaper, would help many Americans to give up meat.

The company is partly funded by Khosla Ventures, Bill Gates and Google Ventures. Google co-founder Sergey Brin previously helped fund a $300,000 beefburger created in a test-tube at Maastricht University in the Netherlands in 2013.

ONE DAY WITHOUT MEAT

Meat is offered for sale at a street market in Paris Thomson Reuters

Elsewhere, a delegation from the Buddhist Tzu Chi Foundation was attempting to promote Jan. 11, 2016, as a Day of Meatlessness.

"It is just one day, but it will help people think about the environmental, ethical, and health issues around meat, and maybe it will grow," said volunteer Lori Chen. "We know you have to move slowly, and be less forceful on issues of diet."

Often, it is a question of social norms. "In France, they take offense if you don't eat meat, like you are rejecting their culture," said Chen. "In China, you are emasculated if you only eat plants," added Hanford Lin, who works for the foundation's fundraising arm.

One person at the conference who is decidedly not emasculated - actor, bodybuilder and former California governor Arnold Schwarzenegger - told reporters on Monday there was no reason why vegetarians could not achieve a muscular physique.

"I have seen many bodybuilders and lifters who are vegetarians and get strong and healthy," he said. "I think it is a good idea, but ... you have to start slowly, you can't just convince people to stop eating meat altogether."

For now, though, meat consumption is rising in the United States, China, and elsewhere despite health warnings, most recently a World Health Organization report that found eating processed or red meat increased the risk of developing cancer.

The British think tank Chatham House says that merely applying existing recommendations from health bodies to limit meat consumption would generate a quarter of the remaining emissions reductions needed to keep global warming below 2 degrees Celsius, a key target of the Paris talks.